Re: CM690 Mods :)
Haha I had to do the same thing on my old board (same as yours), but that didn't fix the problem unfortunately. I also have the EXACT same ram config (a pair of older one and a pair of newer ones). See?
Desktop: Phenom II B50 3.1Ghz, 4GB DDR2 800, Gigabyte MA790X-UD4P, 2x 1TB RAID0, GTX 460 1GB, OCZ 600W, ABS Black Pearl
Laptop: i5 430M 2.26Ghz, 4GB DDR3 1066, 500GB WD Blue, Mobility Radeon HD 5650 1GB (discrete)